The present invention relates to devices and methods for enhancing the fluency of persons who stutter.
Conventionally, stuttering has been treated by several different types of treatment, including psychiatric therapy, drug therapy, and the use of altered auditory feedback, generated by electrical signal processing devices, relayed to the person who stutters. These techniques can be generally characterized as either endogenous alterations of the speech signal output, such as prolonged or slowed speech, rhythmic speech, signing, and lipped speech, or exogenous dynamic alterations of the speech signal itself, both of which can successfully induce relatively fluent speech in people who stutter. See, e.g., O. Bloodstein, A Handbook on Stuttering (5th ed. Singular, San Diego, Calif., 1995).
It is believed that exogenous auditory alterations of speech, such as chorus reading, shadow speech, delayed auditory feedback, and frequency altered feedback, or a visual modality of treatment, such as visual choral speech, can generally produce more powerful and natural sounding reductions in stuttering than incongruous non-speech auditory inputs, such as masking noise and clicking, or visual inputs, such as flashing lights.
Two types of altered auditory feedback which have been used to treat stuttering include delayed auditory feedback (xe2x80x9cDAFxe2x80x9d) and the introduction of a masking noise or masked auditory feedback (xe2x80x9cMAFxe2x80x9d). Generally described, DAF imposes a delay on the delivery of a feedback speech signal to a speaker/stutterer, while MAF serves to compete with a speaker""s auditory feedback.
For example, M. E. Wingate, in Stuttering: theory and treatment, p. 237 (Irvington, 1976), describes a type of altered auditory feedback which can include DAF to provide emphasis on phonation, i.e., slowing speech down to extend syllable duration. However, this type of auditory feedback or fluency enhancement is conventionally thought to be achievable with or without the use of DAF as long as syllable prolongation was employed. See, e.g., W. H. Perkins, From Psychoanalysis to Discoordination, in H. H. Gregory (Ed.) Controversies about stuttering therapy, pp. 97-127 (University Press, 1979). See also Andrew Stuart et al., Fluent Speech, Fast Articulatory Rate, and Delayed Auditory Feedback: Creating a Crisis for A Scientific Revolution?, 82 Perceptual and Motor Skills, pp. 211-218 (1996).
Generally stated, the reduction in stuttering frequency under speech signal alterations has been attributed to entrained rhythm, distraction, modified vocalization, and rate reduction. Indeed, in the past, slowed speech rates were found to be an important factor in the reduction of stuttering. For example, in W. H. Perkins et al., Phone rate and the effective planning time hypothesis of stuttering, 29 Jnl. Of Speech and Hearing Research, 747-755 (1979), the authors reported that stuttering was virtually eliminated when speakers reduced speech by approximately 75%. However, other reports have found that rate reduction is neither necessary, nor sufficient, for fluency enhancement. See Kalinowski, et al., Stuttering amelioration at various auditory feedback delays and speech rates, European Journal of Disorders of Communication, 31, 259-269 (1996); Stuart et al., Fluent speech, fast articulatory rate, and delayed auditory feedback: Creating a crisis for a scientific revolution?, Perceptual and Motor Skills, 82, 211-218 (1996); MacLeod, et al., Effect of single and combined altered auditory feedback on stuttering frequency at two speech rates, Journal of Communication Disorders, 28, 217-228 (1995); Kalinowski et al., Effect of normal and fast articulatory rates on stuttering frequency, Journal of Fluency Disorders, 20, 293-302 (1995);. Hargrave et al, Effect of frequency altered feedback on stutterers"" fluency at two speech rates, Journal of Speech and Hearing Research, 37, 1113-1119 (1994); and Kalinowski et al., The effects of alterations in auditory feedback on stuttering frequency, Language and Speech, 36, 1-16 (1993).
Recently, a portable therapeutic device and related stuttering enhancement treatment methods were described in U.S. Pat. No. 5,961,443 to Rastatter et al., the contents of which are hereby incorporated by reference as if recited in full herein. These devices and methods employ altered auditory feedback (auditory delay and/or frequency shift signals) to be delivered to a stutterer via a portably configured device. Despite the above, there remains a need to provide improved methods and devices for treating stuttering to enhance fluency in an effective easily implemented manner.
These and other objects are satisfied by the present invention by methods and devices which employ a xe2x80x9csecondxe2x80x9d exogenously generated speech signal which is produced by a sound or sounds corresponding to spoken vocal utterances or natural speech (independent of the in situ uttered speech of the speaker/stutterer). The second exogenous speech signal can alternatively be generated by other than spoken speech so as to simulate natural speech sounds (such as generated electronically, mechanically, or electromechanically); these simulated sound(s) should be configured to simulate the voice gestures which trigger the auditory cortex of the speaker. The second speech signal of the instant invention can be used as an alternative to DAF or MAF, which typically manipulates, alters, or interferes or competes with the contemporaneous speech of the speaker himself (or herself). The second speech signal of the instant invention is an auditory stimulus which is a spoken speech signal (that is, a voice gesture associated with a vocal cord of a person). The second speech signal can be either stuttered or fluent, and/or coherent (a string of meaningful sounds forming words) or incoherent (the sound(s) having no understandable or meaningful content).
Preferably, the second speech signal comprises a prolonged uttered or spoken sound associated with a natural voice gesture such as a single syllabic vowel or consonant or a combination of vowels and/or consonants. The second speech signal of the instant invention can be relayed to the user such that it is intermittent, sustained for a determined period of time, or substantially continuous with the speech production of a user/patient undergoing treatment for stuttering.
Preferably, the second or exogenously generated auditory speech signal of the instant invention is generated exogenously by someone other than the speaker or patient/stutterer (or generated by a device which can substantially replicate a vocal tract output in order to trigger the auditory cortex of the speaker, as noted above). It is also preferred that the second speech signal be recorded and stored in advance of use such that it can be conveniently and reliably provided or audibly relayed to the speaker at a desirable time (and repeatable at appropriate times).
In one embodiment, the exogenously generated second speech signal is a spoken prolonged speech sound (such as the last sound in the word xe2x80x9csuddenxe2x80x9d). It is more preferred that the prolonged speech sound is a steady state single syllabic sound. It is still more preferred that the prolonged speech sound is a vocal tract output associated with producing a steady state vowel sound. The exogenously generated speech signal can be provided at the start of speech of a person or patient prone to stuttering and/or episodically during speech, such as when a person starts to stutter or is experiencing a stuttering event, or even just at intervals during fluent speech to inhibit the onset of a stuttering event.
The second speech signal can be provided as an arrangement of different voice gesture sounds, the output of which can be varied to alter the exogenously generated speech signal auditory stimulus provided to the patient, over time.
In preferred embodiments, the second or exogenously generated speech signal is pre-recorded and relayed to the user at a desired or appropriate times (either as activated by user input or automatically activated upon detection of a stuttering event). The volume and/or duty cycle of the output are preferably variable to allow a user to adjust the output to his or her needs. That is, in one embodiment, the user can increase or decrease the duration or frequency of the transmitted second speech signal from a continuum ranging from continuously outputting the signal during speech production or a desired output time period to intermittently outputting the signal at desired adjustable intervals during the desired output period.
The second speech signal can be held in and delivered by portable miniaturized devices such as ITE (in the ear), BTE (behind the ear) or OTE (over the ear) stuttering aid devices. Alternatively, the second speech signal auditory stimulus can be generated from stand-alone handheld devices with speakers (or provided as an audio medium such as a compact disk or tape, or downloadable computer code, or other computer readable program formats) or incorporated into communication devices having voice or microphone inputs (such as the handset or base of a telephone or wireless telephone body, two way headsets, and the like) or other devices such as writing implements and the like. In other embodiments, the second speech signal can be held in or incorporated into an audio chip or DSP incorporated into (wrist) watches, bracelets, lapel pins, necklaces or other proximately worn (within the audible range of the user) jewelry such as necklaces and earrings, or headbands, hats, and the like.
One aspect of the invention is a method for enhancing the fluency of persons who stutter, comprising the steps of (a) exogenously generating a speech signal (independent of the contemporaneous speech production of a patient); (b) producing speech by the patient having a propensity to stutter; and (c) delivering the exogenously generated speech signal to the patient temporally proximate to the producing step such that the exogenous speech signal is audible thereto.
In a preferred embodiment, the exogenously generated speech signal is stored or pre-recorded to be repeatedly played back and/or audibly transmitted to the patient at desired intervals or at appropriate times. It is also preferred that the exogenous or second speech signal be generated by a person other than the patient.
Another aspect of the present invention is directed to a device to enhance the fluency of persons who stutter. The device comprises an audio storage medium comprising at least one pre-recorded auditory stimulus speech signal thereon and a speaker operably associated with the audio storage medium to output the speech signal therefrom. The device also includes a power source in communication with the audio storage medium and speaker and an activation switch operably associated with the power source. The device is configured such that the auditory stimulus or second speech signal can be repeatedly output to a user at desired times corresponding to at least one of during an episodic stuttering event; in advance of a speaking event (the production of speech on the part of the user); and during a speaking event to thereby provide an auditory stimulus to the user/person who stutters to enhance the fluency of speech thereof.
In a preferred embodiment, the device includes a user input trigger switch operably associated with the speaker. The user input trigger switch is configured to accept user input to initiate a substantially immediate delivery of the auditory stimulus (second speech signal) such that it is audible to the user. The device can also include an intermittent output switch or button that can allow a user to determine the length, or repeating cycle of the transmitted output signal (to allow the user to vary the auditory stimulus). Similarly, the device can include a selectable signal button to allow the user to select which signal will be transmitted or to vary the output signal automatically over desired time periods.
In one embodiment, the device further includes a microphone and a signal processor configured to receive a signal generated by the user""s speech. In this embodiment, the device can then automatically output the auditory stimulus speech signal to the user based on an analysis of a received signal associated with the user""s speech, such that the auditory stimulus speech signal is provided substantially contemporaneously with the user""s speech independent of (without) auditory feedback or manipulation of the user""s contemporaneous speech itself. Advantageously, the auditory stimulus speech signal is delivered in a manner which allows the user to speak at a substantially normal speech pace.
The device can also be configured to identify the initiation of speech production on the part of the user and the termination of speech by the user by monitoring the signal received by the microphone and signal processor. The device can substantially continuously or intermittently output the auditory stimulus speech signal while the user is speaking (such as concurrent with or during the speech of the user).
In one embodiment, the device can also include a detector operably associated with the processor and receiver (microphone). The detector is configured to detect the onset of or an actual stuttering event, and, in operation, upon recognition of the initiation of an impending or actual stuttering event on the part of the user, the device can output the auditory stimulus speech signal to the user.
As noted above, the auditory stimulus speech signal can comprise a plurality of different natural speech prolonged sounds associated with voice gestures which are independent of the contemporaneous speech of the user and can be configured to be serially output to the user.
Advantageously, the exogenously generated or second spoken speech signal is a vocal communication, utterance, or speech sound(s) which is incongruent with the speech production of the stutterer/user. The present invention, thus, provides an auditory stimulus which can be an effective acoustic mechanism to enhance the fluency in persons who stutter while also allowing users to speak at a substantially normal pace and without requiring the use of DAF or MAF. The second stimulus speech signal can be meaningful or not meaningful and can be presented in incongruent text or spoken speech at normal or stuttered fluency or in steady state spoken speech signals having appropriate duration or prolonged or sustained voice gesture sounds.
The foregoing and other objects and aspects of the present invention are explained in detail in the specification set forth below.